The present invention relates to biological vessel suspending assemblies and systems and methods utilizing same, which can be used, for example, in treating urinary incontinence associated with abnormal bladder neck positioning.
Urinary incontinence is characterized by the involuntary loss of urine in individuals. Urinary incontinence affects approximately 13 million people in the United States alone, 85% of them women. Urinary incontinence can be caused by physical stress (stress incontinence) typically brought on by heavy object lifting, coughing, laughing or sneezing, an overactive bladder (typically referred to as urge incontinence) or by an uncontrollable slow leak which is termed flow incontinence, and which is often experienced when complete bladder emptying can not be achieved by an individual. Additional but less common types of urinary incontinence include functional incontinence and unconscious or reflex incontinence.
Of the above causes for urinary incontinence, stress incontinence and urge incontinence are considered the most prevalent. Stress incontinence can be caused by anatomic abnormalities in the positioning of the bladder or bladder neck or by sphincter dysfunction. Urine loss occurs when the intravesical pressure (i.e., the pressure within the urinary bladder) exceeds, even by a small amount, the maximum urethral pressure (i.e., the pressure on the urethra to maintain closure). While the problem of stress incontinence occurs in both men and women, it predominantly occurs in women of childbearing age and beyond.
There are several methods and devices which can be used to alleviate involuntary loss of urine in people suffering from incontinence. Surgery is perhaps the most desirable method in cases of severe incontinence in younger patients. The surgical alternative often involves a procedure whereby the bladder neck is suspended such that the bladder assumes a normal position.
For severe cases of stress incontinence, the surgeon may secure the bladder with a wide sling positioned under the urethra. Such a sling supports the bladder and in addition compresses the bottom of the bladder and the top of the urethra, further preventing leakage.
Abdominal Suspension Procedures
One abdominal suspension procedure is the Marshall Marchetti Krantz (MMK) procedure which is still offered in many medical centers throughout the United States although it is no longer the method of choice.
In the MMK procedure, the bladder neck and urethra are separated from tie back surface of the pubic bone. Sutures are placed on either side of the urethra and bladder neck, which are then elevated to a functional position. The free ends of the sutures are anchored to the surrounding cartilage and pubic bone.
The Burch procedure, also known as Burch colposuspension (vaginal suspension), is often performed in conjunction with an invasive surgical procedure such as abdominal hysterectomy (removal of the uterus). During the suspension procedure, sutures are placed laterally (sideways), this avoiding urethral obstruction and allowing the physician to repair any small cystoceles that may be present. The bladder neck and urethra are separated from the back surface of the pubic bone and the bladder neck is then elevated via lateral sutures that pass through the vagina and Cooper""s (pubic) ligaments. The vaginal wall and ligaments are brought together without tension, and the sutures are tied.
Needle Suspension
Needle suspension procedures are simpler to perform and are less invasive than abdominal suspension procedures. Numerous types of transvaginal (through the vagina) needle suspension procedures are known in the art.
In transvaginal needle suspension procedures, sutures are placed blindly through the pubic skin or via a vaginal incision into the anchoring tissues on each side of the bladder neck. The bladder neck is then supported by the sutures, which are tied to the fascia (fibrous tissue) or the pubic bone. Operative times and recovery periods are typically shorter in needle suspension techniques as compared to abdominal suspension procedures.
To enhance tissue anchoring, some needle suspension techniques employ bone anchors such as those provided by the Vesica(trademark) and Intac/Infast(trademark) bladder suspension kits.
Sling Procedures
Patients with severe stress incontinence and intrinsic sphincter deficiency (Type III SUI or weakening of the urethra muscle) may not be treatable via the suspension procedures described hereinabove. Such individuals are good candidates for a pubovaginal sling procedure, which can create the urethral compression necessary to achieve bladder control.
This technique involves the creation of a sling from a strip of tissue taken from the patient""s abdominal fascia (fibrous tissue); occasionally, surgeons use a synthetic sling, although urethral erosion appears to be more common when synthetic slings are used.
The strip of fascia is obtained via an incision above the pubic bone. Another incision is made in the front of the vaginal wall, through which the surgeon can grasp the sling and adjust its tension around the bladder neck. The sling is secured in place by sutures which are loosely tied to each other above the incision in the pubic fascia, thus providing a hammock for the bladder neck to rest in.
The pubovaginal sling procedure generally results in high success rates, with bladder control lasting more than 10 years, although complications such as accidental bladder injury, wound infections and prolonged urinary retention severely limit the effectiveness of this technique.
The Vesica(trademark) sling procedure employs two small anchors which are secured into the pubic bone in order to provide stable fixation for a synthetic or natural tissue sling which functions in supporting tie urethra, bladder neck and sphincter.
The Precision Tack(trademark) transvaginal anchor system also employs bone anchors which are secured into the backside of the pubic bone via a minimally invasive procedure. These anchors are connected to a sling via sutures, which sling then functions like a hammock, to support the bladder in a functional position.
Although the above described surgical procedures provide solutions to individuals suffering from urinary incontinence, such procedures suffer from several inherent limitations including the inability to properly tension supporting sutures, which inability results in urethral obstruction thus making self-catheterization or additional surgical intervention necessary.
Limitations of prior art suspension techniques are the major causes underlying a reported 50 to 60% failure rate which is observed therewith following 3 years of service.
In addition, limitations inherent to bladder neck/urethra positioning techniques used by surgeons prior to or during a surgical suspension technique often lead to bladder neck mis-positioning and reduced bladder function.
There is thus a widely recognized need for, and it would be highly advantageous to have, a biological vessel suspending assembly which can be utilized for accurate bladder suspension while being devoid of the above limitations.
According to one aspect of the present invention, there is provided a biological vessel supporting assembly comprising: a mounting element including at least one anchoring device for anchoring the mounting element within the body cavity; and a sling mountable at its opposite ends to the mounting element and dimensioned to support the biological vessel when the sling is mounted to the mounting element; the sling being adjustably mountable at its opposite ends along the mounting element such as to permit the sling, and the biological vessel when supported thereon, to be precisely positioned within the body cavity.
According to further features in the described preferred embodiments, the sling is of a circular configuration in cross-section such as to produce a low-friction sling contact between the sling and the biological vessel, and thereby to minimize the possibility of damage to the biological vessel when moved with respect to the sling.
According to still further features in the described preferred embodiments, the mounting element includes a flexible suspension strand, and an anchoring device at each of the opposite ends of the suspension strand for mounting the strand in suspension within the body cavity. The sling also includes a flexible strand adjustably mountable at its opposite ends to the flexible suspension strand. Preferably, both the suspension strand and the sling strand are of a flexible, tubular mesh material.
According to still further features in the described preferred embodiments, the sling includes a slider cuff at each of its opposite ends for slidably mounting the opposite ends of the sling to the suspension strand.
According to still further features in the described preferred embodiments, the assembly further comprises an anchor inserter device removably engageable with each of the anchoring devices for inserting the anchoring device into tissue within the body cavity when mounting the suspension strand therein.
According to another aspect of the present invention, there is provided a biological vessel supporting assembly for supporting a biological vessel within a body cavity, comprising: an elongated, flexible suspension strand having an anchoring device at each of its opposite ends for mounting the suspension strand within the body cavity; and a flexible sling strand mountable at its opposite ends to the suspension strand and dimensioned to support the biological vessel; the sling strand, when mounted at its opposite ends to the suspension strand, being movable along the suspension strand such as to permit the sling strand, and the biological vessel when supported thereon, to be precisely positioned within the body cavity.
According to a still another aspect of the present invention, there is provided a method of supporting a biological vessel within a body cavity, comprising: anchoring a mounting element to tissue within the body cavity; mounting a sling to the mounting element; supporting the body cavity on the sling; and moving the sling, and the body cavity supported thereon, along the mounting element to precisely position the biological vessel within the body cavity.
The present invention successfully addresses the shortcomings of the presently known configurations by providing a biological vessel suspending assembly which when utilized for treating urinary incontinence, can be positioned and adjusted through a single trans-vaginal incision rather than the three incisions required for positioning and adjustment of most prior art incontinence systems.